Does anyone know how PSA’s 14.7” mid-length upper performs compared to that of the carbine gas system? Is the mid-length under pressured when using weaker (steel cased) ammunition such as Wolf? This information would be of great help to me given that I cannot decide for the life of me which gas system I should go with. Any other feedback with these two configurations would be greatly appreciated. Thank you!

My personal mid-length rifle will not cycle cheap steel cased ammo (Tula/Wolf) using an H2 buffer. Seems to work fine with a carbine or H buffer, but your results may vary.

Interesting to note that I can shoot MFS steel cased without issue with an H2 buffer.

I appreciate your input! Does the 'Premium Classic M4 Stock Kit' come with a carbine buffer? Just to clarity, when you say it wont cycle are you referring to it not locking back on empty or a different issue? Why would my results vary? Are you implying that not all PSA 14.7" mid-length upper's are identical? I apologize for being so detail oriented. I just want to be educated on this topic. Thank you!

That kit comes with a standard carbine buffer. Tula/Wolf will not cycle reliably with a heavier buffer in my rifle. I am sure you will have the same results as I do, but I don't want to guarantee that since cheaper ammo like Tula/Wolf can be inconsistent.

The only steel cased ammo I will shoot now is MFS as I haven't experienced an issue with it, and it's not as dirty.